1. Field of the Invention
The present invention generally relates to a system and method for a retrofit mechanism for motorizing a manual turret.
2. Background Art
Many military vehicle vehicles (e.g., an M-1114 High Mobility Multipurpose Wheeled Vehicle, HMMWV) have a turret assembly mounted on a relatively stationary section (e.g., vehicle body). Such turret mechanisms often include weaponry (e.g., machine guns, rocket launchers, and the like), boom assemblies, audio equipment, nozzles, etc. as well as such assemblies as attack protective equipment, weather protective equipment, operation devices, etc. The turret assembly on many of such vehicles is normally manually slewed (i.e., traversed, rotated, moved about a normally vertical axis, laterally aimed, rotationally positioned side-to-side, moved clockwise or counterclockwise, etc.). Similarly, turret mechanisms can be mounted and manually slewed in connection with non-vehicle (e.g., watercraft, land-based installations, aircraft, etc.) implementations.
When the weight of the turret mechanism is increased (e.g., when additional equipment is added to the devices already on the turret assembly) beyond certain limits, the manual slewing operation of the turret becomes too difficult for a person of normal stature (e.g., a person in a 50th percentile) to accomplish in a practical manner. For example, when a M1114 HMMWV turret having a weapon, gun shield and ammunition is equipped with a gunner protection kit (GPK), the combined weight is over 550 lbs.
One conventional approach to improving the ability of a person having a normal stature to manipulate (slew) a massive turret assembly (i.e., a turret assembly having weight beyond typical human limits to slew without aid) is to provide mechanical assistance (e.g., a hand crank with gear reduction to provide a mechanical advantage) to the turret assembly.
Without the hand crank assembly assistance, and sometimes due to high stresses involved, overcompensation (e.g., slewing past a desired target zone) and operator fatigue can, at the extreme, lead to slewing the turret out of control. Such a situation is obviously hazardous when, for example, the operator is attempting to maneuver a turret mounted weapon into firing position, especially when the vehicle where the turret is installed is on an incline that adds additional gravitational forces that must overcome.
However, even implementation of a hand crank assembly has deficiencies in that for proper ergonometric considerations, the gear reduction is such that the hand crank can be operated by a 5th percentile female soldier which generally slows the slewing operation considerably, the hand crank assembly is incorporated in connection with a hand brake which must be released before the turret can be slewed and reset after the turret is slewed which also slows the slewing operation as well as causing a distraction, the hand crank assembly adversely encroaches on a 95th percentile male gunner envelope thus causing a reduction in space and mobility for such a gunner, and the crank assembly protrudes such that the gunner or equipment can bump or snag on the crank assembly.
As such, another approach to slewing a massive turret assembly is to provide motorized assistance under the control of an operator (e.g., the gunner). The motorized assistance is often implemented via an electrical motor (and gear box) assembly. However, conventional turret mounted electrical motors are typically implemented having electrical energy provided from the body of the vehicle upon which the turret is mounted.
Conventional approaches for providing electrical energy to and from electrical devices (e.g., motors, batteries, motorized pumps, capacitors, etc.) that are installed on rotating turrets often include slip ring or multi-geared ring and contactor assemblies. However, such assemblies are generally expensive (costly), prone to increase electrical path resistance and loss of electrical continuity due to damage and corrosion, require area on the turret and mount when the amount of desired area may already be limited, require extensive modification to a structure such as the turret and the turret mounting that was not initially designed for a motorized assembly, etc.
Another conventional approach for providing electrical energy to and from electrical devices that are installed on rotating turrets is to directly electrically connect the turret to the relatively stationary section of the vehicle (e.g., electrically hard wire the vehicle body and the turret together via electrical cabling or wiring) and to limit the amount (i.e., angle) of rotation that the turret is permitted to traverse. Such an approach has the deficiency of limiting the useful angular range of the vehicle where the turret is mounted. Such turret rotation angular limitations are generally unacceptable for military vehicles. The conventional slip ring or multi-geared ring and contactor assemblies, and the conventional direct hard wiring approaches may also tax limited vehicle electrical power capacity.
Further, the equipment that is installed on a turret is often positioned primarily at one side of the turret. Such a placement can cause the turret to be unbalanced (i.e., the center of gravity of the turret may be significantly skewed from the axis of rotation of the turret). Conventional approaches to counter-balancing turrets and the like include counter-balance springs, operator seating to use operator weight as a weight offset, and counter-balance ballast material such as cast iron blocks. However, such conventional approaches have deficiencies that include the addition of cost and weight, restriction of operator movement, and reduction of usable space.
Thus, there exists a need and an opportunity for an improved system and method for a retrofit unit for motorizing a manual turret. Such an improved system and method may overcome one or more of the deficiencies of the conventional approaches.